Rare Antique 1920s RI (Radio Instruments Ltd) Multivalve Transformer Pat 230981

ON AUCTION IS A RARE ANTIQUE RI (RADIO INSTRUMENTS LTD) MULTIVALVE TRANSFORMER. I COULD FIND ONLY ONE SIMILAR ONE ONLINE.
 
THESE TYPE OF TRANSFORMERS WERE USED IN THE POWER SUPPLY OF OLD RADIOS TO STEP DOWN MAINS VOLTAGE TO SAFE LEVELS AND PROVIDE SPECIFIC VOLTAGES FOR THE TUBES (FILAMENTS AND PLATE VOLTAGE), AND IN AUDIO STAGES FOR IMPEDANCE MATCHING AND AMPLIFYING LOW-GAIN TRIODES. 
 
In old tube radios, they perform the crucial function of isolating the radio's circuitry from the high voltage of the electrical mains. They step the incoming voltage down to the lower, safer levels required by the radio's components. A power transformer contains windings that provide the low voltages (e.g., 6.3V, 12.6V) needed to heat the filaments of the vacuum tubes, allowing them to operate. 
 
IT WAS ALSO USED TO STEP DOWN THE HIGH AC VOLTAGE FROM THE MAINS TO THE LOWER VOLTAGES NEEDED FOR OLD VACUME TUBE LOUDSPEAKER AMPLIFIER'S CIRCUITRY.
 
DIMENSIONS: 8.5CM WIDE 11CM HIGH 5CM DEEP
 
CONDITION: ALL VALVES STILL LOOSE. OF ANTIQUE UNTESTED AGE.
 
RADIO INSTRUMENTS LTD:
Radio Instruments Ltd., founded in 1922, was a pioneer in British electronics, producing radios, components, and later, specialized equipment for the military. In 1936, it was acquired by Aeronautical and General Instruments Ltd. (AGI). AGI expanded its product range to include sound ranging, signalling, direction finding, and navigational devices. Following World War II, AGI continued to innovate, producing cameras, communications equipment, and advanced meteorological systems. Today, AGI remains a significant player in the fields of instrumentation, aviation, and meteorology.
 
PLEASE ALSO SEE MY OTHER ITEMS LISTED. I HAVE SOME INTERESTING ITEMS ON AUCTION THIS WEEK. COPY THE URL UNDERNEATH AND PASTE INTO GOOGLE AND IT WILL TAKE YOU DIRECTLY TO ALL MY LISTINGS THIS WEEK. NOTE ALL MY AUCTIONS END AT 22H30 SO IT IS ADVISABLE TO PUT IN AN AUTOMATIC BID (HIGHEST PRICE YOU ARE WILLING TO PAY) EARLY.
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